Huff-n-puff recovery performance and mechanism analysis of black nanosheets in low-permeability reservoirs based on NMR technology

IF 6.1 1区工程技术 Q2 ENERGY & FUELS

Petroleum Science Pub Date : 2025-07-01 DOI:10.1016/j.petsci.2025.05.023

Si Guo, Hong-Bin Cheng, Hong-Gen Tan, Hong-Yu Li, Jiong Zhang, Ying-Qi Gao, Dao-Yi Zhu

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引用次数: 0

Abstract

Black nanosheets (BNs), as a highly promising fracturing-EOR integrated enhancement material, require further study of their huff-n-puff performance and mechanism. This work characterized nanoscale structure, stability, and interfacial properties of BNs, then evaluated their huff-and-puff performance through NMR-assisted core flooding experiments. The adaptability of BNs in low-permeability reservoirs with different permeabilities, as well as the effect of huff-n-puff cycles on their oil recovery performance, were analyzed. Results show that anionic modified BNs maintained nanoscale flake structure with enhanced electrostatic repulsion. The BNs with an extremely low concentration of 0.002 wt% exhibited excellent emulsification and stabilization effects on crude oil and wettability alteration of the rock surface. Compared with injection water, BNs had excellent huff-n-puff oil recovery effects, reaching 22.1% original oil in place (OOIP) after the first huff-n-puff cycle. BNs had good adaptability in low-permeability cores (i.e., 0.1 × 10⁻³ to 10 × 10⁻³ μm²). Increasing the huff-n-puff cycle significantly improved the oil recovery effect of BNs, and the optimal performance was at 4 cycles. As the huff-n-puff cycle increased from 3 to 4, the ability of BNs to “automatic oil-seeking” in micropores became more prominent. This paper also innovatively combined core nuclear magnetic resonance (NMR) T₂ analysis, nuclear magnetic imaging analysis, and longitudinal T₂ signal analysis along the core (i.e., along the core injection length). It can not only more accurately quantify the huff-n-puff recovery effect of low-permeability cores but also quantitatively analyze the penetration depth and microscopic huff-n-puff mechanism of BNs from a microscopic perspective. These findings are helpful for the selection of nanomaterials and mechanism analysis in the design of integrated fracturing-flooding schemes and processes.

查看原文本刊更多论文

基于核磁共振技术的低渗透储层黑色纳米片采收率及机理分析

黑色纳米片作为一种极具发展前景的压裂-提高采收率综合增强材料，其吞吐性能和机理有待进一步研究。本研究表征了BNs的纳米级结构、稳定性和界面性质，然后通过核磁共振辅助岩心驱油实验评估了它们的涨落性能。分析了BNs在不同渗透率低渗透油藏中的适应性，以及吞吐循环对其采收率的影响。结果表明，阴离子修饰的氮化硼保持了纳米级片状结构，静电斥力增强。极低浓度（0.002 wt%）的bn对原油和岩石表面润湿性的改变具有良好的乳化和稳定作用。与注水相比，BNs具有较好的吞吐采油效果，在第一次吞吐循环后达到22.1%的原始产油量（OOIP）。BNs在低渗透率岩心（0.1 × 10−3 ~ 10 × 10−3 μm2）中具有良好的适应性。增加吞吐周期显著提高了bn的采油效果，在4次循环时表现最佳。随着“吞吐”周期从3次增加到4次，有机质在微孔中的“自动寻油”能力更加突出。创新性地将岩心核磁共振（NMR） T2分析、核磁共振成像分析、沿岩心方向（即沿岩心注入长度方向）纵向T2信号分析相结合。不仅可以更准确地量化低渗透岩心的鼓泡采收率效果，还可以从微观角度定量分析bn的侵彻深度和微观鼓泡机理。这些研究结果有助于在设计压裂-驱油一体化方案和工艺时进行纳米材料的选择和机理分析。

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来源期刊

Petroleum Science 地学-地球化学与地球物理

CiteScore

7.70

自引率

16.10%

发文量

311

审稿时长

63 days

期刊介绍： Petroleum Science is the only English journal in China on petroleum science and technology that is intended for professionals engaged in petroleum science research and technical applications all over the world, as well as the managerial personnel of oil companies. It covers petroleum geology, petroleum geophysics, petroleum engineering, petrochemistry & chemical engineering, petroleum mechanics, and economic management. It aims to introduce the latest results in oil industry research in China, promote cooperation in petroleum science research between China and the rest of the world, and build a bridge for scientific communication between China and the world.